title: Monte Carlo and theoretical calculations of the first four perturbation coefficients in the high temperature series expansion of the free energy for discrete and core-softened potential models.
abstract: The first four perturbation coefficients in the expansion of the Helmholtz free energy in power series of the inverse of the reduced temperature for a number of potential models with hard-sphere cores plus core-softened and discontinuous tails are obtained from Monte Carlo simulations. The potential models considered include square-well, double square-well, and square-shoulder plus square-well, with different potential parameters. These simulation data are used to evaluate the performance of a traditional macroscopic compressibility approximation (MCA) for the second order coefficient and a recent coupling parameter series expansion (CPSE) for the first four coefficients. Comprehensive comparison indicates the incapability of the MCA for the second order coefficient in most non-stringent situations, and significance of the CPSE in accurately calculating these four coefficients.
authors.affiliation: School of Physics and Electronics, Central South University, Changsha, Hunan 410083, China. chixiayzsq@yahoo.com
authors.forename: Shiqi
authors.initials: S
authors.lastname: Zhou
authors.forename: J R
authors.initials: JR
authors.lastname: Solana
mesh_terms: D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D009010:Monte Carlo Method; D013816:Thermodynamics